Continuous folded gusset for school bags



Jan. 23, l951 P BENENFELD 2,539,051

CONTINUOUS FOLDED GUSSET FOR SCHOOL BAGS Filed Fb. 4, 1948 Ihmentor Peer enenfeld Gttomeg Patented Jan. 23, 1951 UNITD STATES PATENT OFFICE CONTINUOUS FOLDED GUSSET FOR soHoOL BAGS Peter Benenfeld, New York, N. Y.

Application February 4, 1948, Serial No. 6,180

' `v9 Claims. (Cl. 150-1.6)`

l I his invention relates to eXpansible hand bags and particularly to the gusset thereof, and to the method of securing and folding the gusset. The invention contemplates the provision of a continuous gusset made oi a strip of flexible material of uniform width and bent to form the sides and bottom of the bag at the lower rounded corners of the bag, the rear edge of the gusset being so stitched to the peripheral edge portion of the back of the bag as to induce the formation of a longitudinal fold in the gusset intermediate its edges, thereby to permit the front of the bag to register neatly with the back without the necessity of auolding, pressing or other additional operation.

The invention further contemplates the provision of a stifened flange formed by the periph-A eral edge portions of the gusset and Of the back of the bag as well as of a doubly stitched and relatively wide binding strip therefor, whereby the flange is so much stiffer than the gusset, that even at the bends of the gusset at the rounded bag corners, slight pressure such as that caused by the weight of the bag front folds the gusset properly to collapse the iront toward the back along predetermined folds. The invention further contemplates the provision of a method of forming at least two breaks or crease lines automatically in the otherwise cylindrical bend or" the gusset at the rounded corners of the bag, thereby to initiate a fold in the gusset which continues 'therethrough and causes the bag to fold in a predetermined manner. The various objects of the invention will be clear from the description which follows and from the drawings, in which Fig. 1 is a perspective View of a school bag to which the invention has been applied, showing the bag open and omitting the usual front pocket. Y l

Fig. 2 is a fragmentary horizontal sectional View oi an edge portion of the bag, showing the position temporarily and progressively assumed by each part of the gusset during the Sewing thereof in place to form the stiffened edge iiange. Fig. 3 is a similar sectional view of an edge portion of the bag taken on the line 3 3 of Fig. 5, and showing the folded orpartly collapsed posi-'- tion or the gusset assumed thereby after the bag-1 closing operation has been completed and the parts have been released from the stressesapplied thereto during sewing.

Fig. 4. is a similar sectional view of an edge part of the bag taken on the line 1A-d of Fig. which line is arranged between a pair of breaks lor lines or" crease at the rounded corner.

, `2 Fig. 5 is a fragmentary vertical sectional view of the back of the bag and its peripheral flange,

the view being taken on a plane intermediate` the back and front of the bag, but with the front and the attached front part of the gusset removed, and showing the indeterminate form of the breaks or crushed folds of the bends of the gusset.

Fig. 6 is a fragmentary horizontal sectional View of the bag through the binding strip on the uppermost edge of the bag front, and taken on the line E-G of Fig. 1.

The invention is best applied tO aubag having a continuous gusset in the form 'of a'strip Of cloth or the Alike material forming the flexible sides I0 and Il andthe flexible bottom l2 of the bag as viewed in Fig. l. The gussetstrip is preferably of uniform width, free of notches, creases or pre-folds, and is economically secured at its front edge I3 to the peripheral edge portion of the sheet Ill which forms the front of the bag, by a suitable welted seam as I5, which seam is made as a preliminary operation prior to the closing Operation. The front sheet id is provided with lower rounded corners I6 and I1, and the gusset strip as well as the seam I5 are similarly rounded to lit said corners. The gusset strip thereby be-l comes bent at each of the corners I6 and I'I into partly cylindrical form having a warped surface which tends to stiffen the bend and resists the formation of the outwardly concave longitudinal fold I8 in the bag side IB, the fold I9 in the bag side Il and a corresponding fold in the bottom I2. I

It is, however, highly desirable that such folds i3 and I9 become automatically made or at least started in the gusset strip, for the reason that a separate Operation to crease the gusset as required lwould be prohibitively expensive. If the folds are not deliberately formed in the gusset, other objectionable folds tend to form in the front I4 inwardly of the welted seam lil, by reason of the greater stiiness of the cylindrical corners or bends in the gusset strip, which urge the strip to stand more or less erect when the bag is laid down as with its rear face on a work table after the rear ledge of the gusset has beenV secured 'to the edge portion 29 ofthe back 2l.' Shouldthe sides of the bag lean inwardly at the bag opening 22, as it may well do if permitted, instead of fold ing at some longitudinal line between the front and the back, then the front sheet Hi would sag toward the back closing the bag Opening 22, undesirable folds or creases would appear in the front sheet and the bag would assume an unf kempt appearance and would wear out with relative rapidity.

I have found that merely stitching and binding the rear edge 2S of the gusset strip to the corresponding edge portion 29 0f the back 2| does not result in obviating the sagging of the front nor the failure to locate. and arrange the folds I8 and I9 automatically between the edges I3 and 20 of the gusset strip. While such stitching and binding forms a peripheral flange around the bag, the ange does not remain in the plane of the back 2|, but is twisted out off said plane into substantially a continuation of the stiffened cylindrical portions of the gusset at the rounded corners of the bag. 1 have further found that by avoiding or at least substantially resisting much of said twist of the peripheral ange and maintaining the flange 2.3 as nearly as possible in the plane of the back 2 I' (see Fig. 4) two or more breaks; folds or creases as' 2li, 25,` Fig. 5, are autol desired longitudinal folds in the gusset are initiated at said corners and tend naturally to extend themselves completely throughout the lengths of the'si'des and bottom of the bag. To aid in the initiation and formation of thef fol'ds I 8 and I9, the sea-m l5 is preferably biased towardthe gusset during the operation of making the flange. 23 and during the prior operation of attaching the bindi'ngstrip Sito the upper edges of.l the front i4' and or'the gusset'strip.

As shown in Fig'. 6', the top end portion of the seam I5 is stitched to and within; thefolded bind'- ing. strip and between the front flap 3l" and the rear fia-p 3.2. thereof, with the seamed edge parts biased or turned against the gusset and there held. The extra thickness of theseainedY parts serve' tov urge the adjacent. or front part of the gusset to' lie in the same plane as the/front I and to form substantially an extension of said front, whiley therelatively stiff ilang'e 213 holds the rear edge'` portion of the gusset inY substantially the plane: of the rear sheet or back 2i of the bag but with' edge 2li outermost while the front edge I3 of the gusset or the seam I5 isinnermost. The gusset is thus forced toassume an S-like shape in cross section, the concave f fold I8 and thev convex fold. 35 (Fig. 3) being thereby initiatedl As best seen in Fig. 2, biasing of the seam I 5 in the proper direction may be accomplished automatically or assisted manually as the two parallel lines of closing stitching 21 and 28 are made, to form the relatively sti flange 23. This isdone by continuously laying that part of the gusset strip opposite the point where the stitching is done, as atly as possible against the back, with. the. seam l5 turned outwardly. As the stitching progresses, the stitched part is released and the adjacent. part of the gusset temporarily attened until thelange 23 has been formedcompletely around the edge portion of the back 2II.

Said flange 23 comprises the edge portion 20 of.' the gusset, ther registeringl edge portion 29' of the back'in face to face contact therewith, the folded binding. Strip33 of substantial width sufficient to receive and to hold the two rows 21 and 28 of stitching. Preferably, the rows of stitching are spaced apart about 3/16 inch and are spaced from the edges of the binding and the fiange about Jl/a inch to make the flange about r1/ 1s inch wide. The double stitching, which may be made in one operation, and the extra width of the binding stifiens and reinforces the flange to such anextent that itbecomes stiffer than the bends in the gusset and thereby resists twisting into the cylindrical shape which the bent gusset tends to assume, to a greater extent than thebent part'. of the gusset resists deformation.

As the closing stitches 21 and 23 turn the corner as 355 of the ange 23 and pass said corner,` the-diiterence in the radii oi the stitched curvesatsaid corners causes the gusset to fold or crease automatically since the flange is too stiiT to be bent by the released gusset forwardly orrearwardly. However, the body of the gusset, being less sti" and more easily deformed by the collapse-producing forces thereon than the ange. yields to the deforming forces by creasing at a number of points in a more or less indeterminate manner; The relatively weaker gusset therefore collapses to form at least two fold points or breaks 25' and 24- in'the general manner desired, and to initiate the formation of the folds I8 and I9. That part 35' of the gusset adjacent the seam I5" becomes convex outwardly aided thereto by the biasing of the seam' toward the gusset, while the stiiened flange 2S forms' the concave fold I8. With the depths of the flange and folds controlled to a large extent, it becomes possible to arrange the outermost edge of the fold 35 directly in front 0f the outermost edge of the ange 23 thereby to attain the desired neatly folded appearance.

It will now be seen that the iiange 23 is stiff'- sufciently to assure the desired folding of the gusset' particularly at the bends thereof; that suchv stilfening is inexpensively but rapidly and effectively attained by making a double row of stitches simultaneously in a suiciently wide binding strip thereby to prevent such rotation of the flange-about a single line of stitching as would bring the flange forwardly or rearwardly into the cylindrical shape of the bend in the gusset and prevent initiation of the fold therein; that the relatively distorted gusset collapses under the forces thereon to form the desired folds, and that I have produced a gusset structure and method of making the same well designed to meet the requirements of practical use.

While a, certain specific embodiment of the invention has herein been shown and described, various obvious changes may be made therein without departing from the spirit of the invention defined in the appended claims.

I claim:

1. In a bag having a front sheet and aV back sheet, said sheets being provided with rounded bottom corners, a flexible notchless and creaseless gusset of uniform width and of a single thickness of material throughout, interposed between said sheets and having lateral broken cylindrical bends therein conforming generally to and adjacent toY said rounded corners, a welted seam securing the front edge of the gusset to the periphery of the front sheet, anda peripheral flange around the back sheet comprising a binding strip having a longitudinal middle fold therein and having sides depending from the 'fold and arranged about the peripheral edge p0rtion of the' back and the re'ar'edge portion of the gusset to enclose said edge portions, and two parallel rows of stitching through the binding and through the edge portions enclosed by the binding to stiifen the flange against bending excessively out of the plane of the back sheet, those parts of the flange at the rounded bottom corners of the back sheet projecting rearwardly out of said plane and being relatively stii and rigid, said flange being stiffer than the broken cylindrical bends of the gusset, a plurality of differently warped portions in said bends each of a single thickness of gusset material, and longitudinal folds in the gusset terminating at said warped portions.

2. The bag of claim 1 and a second binding strip for the upper edge of the front sheet, the ends of said second binding strip and edge being arranged in the interior of the folded binding strip of the flange and held therein by the rows of stitching.

3. In a bag of the character described, having rounded bottom corners, a back sheet, a continuous gusset of flexible material of uniform width and of a single thickness throughout constituting the sides and bottom of the bag and joining the bottom to the sides by integral generally cylindrical bends therebetween and intermediate the ends of the gusset at said rounded corners, each of the bends being of a single thickness of gusset material, an outstanding flange at the rear edgev of and stiffer than the gusset and including the peripheral portion of said back sheet, a folded binding strip enclosing said portion and the rear edge of the gusset and parallel rows of stiffening stitching through the strip, the gusset and the back sheet, longitudinal rounded folds lengthwise of and in the gusset and a plurality of relatively indeterminate and generally transverse folds each of a single thickness in said bends, those parts of the flange adjacent the generally cylindrical bends of the gusset being each curved through an angle of about 90 and extending slightly rearwardly out of the plane of the remainder of the back sheet.

4. The bag of claim 3 wherein each of the longitudinal folds comprises a concave part of the gusset adjacent and inwardly of the flange and a convex part of the gusset adjacent the front edge of the gusset. Y

5. The method of making a bag having a front sheet provided with lower rounded corner, having a rear sheet provided with lower rounded corners and of substantially the same width as the front sheet, and having a continuous gusset strip of uniform width and of a single thickness of material throughout joining the sheets, said method comprising securing one edge of the strip to the edge of the front sheet by a welted seam, progressively laying the rear edge portion of the strip into registration with the peripheral portion of the back sheet, and binding said edge portions while biasing the welted seam toward the gusset strip and while simultaneously making a double row of parallel stitches therethrough to form a ange stiffer than the gusset, and continuing the binding and stitching past the rounded corners of the back sheet while maintaining the single thickness of the gusset to form a rounded part of the flange and to distort forcibly that part of the gusset adjacent said rounded part into a. plurality of indeterminate folds in a generally cylindrical bend.

6. The method of claim 5 wherein the indeterminate folds initiate longitudinal folds in the gusset.

'7. The method of cla-im 6 wherein the stitching operation distorts the rounded parts of the flange out of the plane of the remainder of the ange, and resisting such distortion of the flange to insure the formation of the longitudinal folds.

8. The method of claim 5 wherein the indeterminate folds break the generally cylindrical bend in a direction generally perpendicular to the flange, and resisting the distortion caused by the stitching operation of the rounded parts of the flange out of the plane of the remainder of the flange.

9. A school bag comprising a generally plane front sheet, a generally plane back sheet higher than the front sheet and in parallel spaced relation thereto and movable forwardly and rearwardly relatively thereto, both sheets having rounded bottom corners, a flexible continuous creaseless and relatively unstretchable gusset of a single length of material and of a single thickness and uniform width throughout, arranged between the marginal side portions of the sheets and between the marginal bottom portions of the sheets, the front marginal portions of the gusset and the marginal portions of the iront sheet adjacent thereto extending rearwardly, a continuous welted seam including a welt and a first visible binding strip enclosing the welt, said seam being arranged between the front marginal portions of the gusset and the marginal portions of the front sheet, stitching through said binding strip and marginal portions of the front sheet and gusset, the marginal portions of the rear edge of the gusset being flat and in contact with the corresponding marginal portions of the front face of the back sheet, a second binding strip around the edge of `the back sheet and enclosing said edge and the rear marginal portions of the gusset to form a peripheral flange, two parallel rows of stiffening stitching through the second binding strip the back sheet and the enclosed rear marginal portions of the gusset, a third binding Strip at and enclosing the upper edge of the front sheet and the upper edges of the gusset and entering and enclosed at its ends by the second binding strip, a generally cylindrical bend in the gusset outstanding forwardly from the flange at each of the rounded bottom corners of the back sheet and of a single thickness of material, a plurality of indeterminate folds each of a single thickness in each of said bends arranged in a direction generally perpendicular to the plane of the flange and taking up the fullness or" the gusset at said bends, a convex longitudinal fold in the length of the gusset terminating at one of said indeterminate folds, and a concave longitudinal fold in the gusset terminating at another` of the indeterminate folds.

PETER BENENFELD.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,143,171 Bushwick June 15, 1915 1,984,150 Ottinger Dec. 11, 1934 2,061,091 Roth Nov. 17, 1936 

